/brz/remove-bazaar

To get this branch, use:
bzr branch http://gegoxaren.bato24.eu/bzr/brz/remove-bazaar
4110.2.2 by Martin Pool
Remove obsolete comments
1
# Copyright (C) 2005, 2006, 2008, 2009 Canonical Ltd
1887.1.1 by Adeodato Simó
Do not separate paragraphs in the copyright statement with blank lines,
2
#
974.1.27 by aaron.bentley at utoronto
Initial greedy fetch work
3
# This program is free software; you can redistribute it and/or modify
4
# it under the terms of the GNU General Public License as published by
5
# the Free Software Foundation; either version 2 of the License, or
6
# (at your option) any later version.
1887.1.1 by Adeodato Simó
Do not separate paragraphs in the copyright statement with blank lines,
7
#
974.1.27 by aaron.bentley at utoronto
Initial greedy fetch work
8
# This program is distributed in the hope that it will be useful,
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11
# GNU General Public License for more details.
1887.1.1 by Adeodato Simó
Do not separate paragraphs in the copyright statement with blank lines,
12
#
974.1.27 by aaron.bentley at utoronto
Initial greedy fetch work
13
# You should have received a copy of the GNU General Public License
14
# along with this program; if not, write to the Free Software
4183.7.1 by Sabin Iacob
update FSF mailing address
15
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
1218 by Martin Pool
- fix up import
16
1231 by Martin Pool
- more progress on fetch on top of weaves
17
18
"""Copying of history from one branch to another.
19
20
The basic plan is that every branch knows the history of everything
21
that has merged into it.  As the first step of a merge, pull, or
22
branch operation we copy history from the source into the destination
23
branch.
24
"""
25
3350.6.4 by Robert Collins
First cut at pluralised VersionedFiles. Some rather massive API incompatabilities, primarily because of the difficulty of coherence among competing stores.
26
import operator
27
4476.3.9 by Andrew Bennetts
Further reduce duplication.
28
from bzrlib.lazy_import import lazy_import
29
lazy_import(globals(), """
30
from bzrlib import (
31
    tsort,
32
    versionedfile,
33
    )
34
""")
1534.1.31 by Robert Collins
Deprecated fetch.fetch and fetch.greedy_fetch for branch.fetch, and move the Repository.fetch internals to InterRepo and InterWeaveRepo.
35
import bzrlib
4110.2.4 by Martin Pool
Deprecate passing a pb in to RepoFetcher
36
from bzrlib import (
37
    errors,
38
    symbol_versioning,
39
    )
4022.1.1 by Robert Collins
Refactoring of fetch to have a sender and sink component enabling splitting the logic over a network stream. (Robert Collins, Andrew Bennetts)
40
from bzrlib.revision import NULL_REVISION
2094.3.5 by John Arbash Meinel
Fix imports to ensure modules are loaded before they are used
41
from bzrlib.trace import mutter
42
import bzrlib.ui
1534.1.31 by Robert Collins
Deprecated fetch.fetch and fetch.greedy_fetch for branch.fetch, and move the Repository.fetch internals to InterRepo and InterWeaveRepo.
43
1238 by Martin Pool
- remove a lot of dead code from fetch
44
1534.4.41 by Robert Collins
Branch now uses BzrDir reasonably sanely.
45
class RepoFetcher(object):
46
    """Pull revisions and texts from one repository to another.
47
2592.4.5 by Martin Pool
Add Repository.base on all repositories.
48
    This should not be used directly, it's essential a object to encapsulate
1534.1.33 by Robert Collins
Move copy_content_into into InterRepository and InterWeaveRepo, and disable the default codepath test as we have optimised paths for all current combinations.
49
    the logic in InterRepository.fetch().
1260 by Martin Pool
- some updates for fetch/update function
50
    """
3172.4.1 by Robert Collins
* Fetching via bzr+ssh will no longer fill ghosts by default (this is
51
4070.9.2 by Andrew Bennetts
Rough prototype of allowing a SearchResult to be passed to fetch, and using that to improve network conversations.
52
    def __init__(self, to_repository, from_repository, last_revision=None,
53
        pb=None, find_ghosts=True, fetch_spec=None):
3172.4.1 by Robert Collins
* Fetching via bzr+ssh will no longer fill ghosts by default (this is
54
        """Create a repo fetcher.
55
4110.2.2 by Martin Pool
Remove obsolete comments
56
        :param last_revision: If set, try to limit to the data this revision
57
            references.
3172.4.1 by Robert Collins
* Fetching via bzr+ssh will no longer fill ghosts by default (this is
58
        :param find_ghosts: If True search the entire history for ghosts.
4110.2.6 by Martin Pool
Remove more progressbar cruft from fetch
59
        :param pb: ProgressBar object to use; deprecated and ignored.
60
            This method will just create one on top of the stack.
3172.4.1 by Robert Collins
* Fetching via bzr+ssh will no longer fill ghosts by default (this is
61
        """
4110.2.6 by Martin Pool
Remove more progressbar cruft from fetch
62
        if pb is not None:
63
            symbol_versioning.warn(
64
                symbol_versioning.deprecated_in((1, 14, 0))
65
                % "pb parameter to RepoFetcher.__init__")
66
            # and for simplicity it is in fact ignored
2668.2.6 by Andrew Bennetts
Merge repository-equality.
67
        if to_repository.has_same_location(from_repository):
2592.3.115 by Robert Collins
Move same repository check up to Repository.fetch to allow all fetch implementations to benefit.
68
            # repository.fetch should be taking care of this case.
2592.4.5 by Martin Pool
Add Repository.base on all repositories.
69
            raise errors.BzrError('RepoFetcher run '
70
                    'between two objects at the same location: '
2592.4.4 by Martin Pool
better message for attempted fetch between aliased repositories
71
                    '%r and %r' % (to_repository, from_repository))
1534.4.41 by Robert Collins
Branch now uses BzrDir reasonably sanely.
72
        self.to_repository = to_repository
73
        self.from_repository = from_repository
4022.1.1 by Robert Collins
Refactoring of fetch to have a sender and sink component enabling splitting the logic over a network stream. (Robert Collins, Andrew Bennetts)
74
        self.sink = to_repository._get_sink()
1534.4.41 by Robert Collins
Branch now uses BzrDir reasonably sanely.
75
        # must not mutate self._last_revision as its potentially a shared instance
1185.65.27 by Robert Collins
Tweak storage towards mergability.
76
        self._last_revision = last_revision
4070.9.2 by Andrew Bennetts
Rough prototype of allowing a SearchResult to be passed to fetch, and using that to improve network conversations.
77
        self._fetch_spec = fetch_spec
3172.4.1 by Robert Collins
* Fetching via bzr+ssh will no longer fill ghosts by default (this is
78
        self.find_ghosts = find_ghosts
1534.4.41 by Robert Collins
Branch now uses BzrDir reasonably sanely.
79
        self.from_repository.lock_read()
4110.2.22 by Martin Pool
Re-add mutter calls during fetch
80
        mutter("Using fetch logic to copy between %s(%s) and %s(%s)",
81
               self.from_repository, self.from_repository._format,
82
               self.to_repository, self.to_repository._format)
3842.3.5 by Andrew Bennetts
Remove some debugging cruft, make more tests pass.
83
        try:
4110.2.3 by Martin Pool
Remove redundant variable from fetch.
84
            self.__fetch()
3842.3.5 by Andrew Bennetts
Remove some debugging cruft, make more tests pass.
85
        finally:
86
            self.from_repository.unlock()
1185.65.27 by Robert Collins
Tweak storage towards mergability.
87
88
    def __fetch(self):
89
        """Primary worker function.
90
3943.8.1 by Marius Kruger
remove all trailing whitespace from bzr source
91
        This initialises all the needed variables, and then fetches the
1185.65.27 by Robert Collins
Tweak storage towards mergability.
92
        requested revisions, finally clearing the progress bar.
93
        """
4022.1.1 by Robert Collins
Refactoring of fetch to have a sender and sink component enabling splitting the logic over a network stream. (Robert Collins, Andrew Bennetts)
94
        # Roughly this is what we're aiming for fetch to become:
95
        #
96
        # missing = self.sink.insert_stream(self.source.get_stream(search))
97
        # if missing:
98
        #     missing = self.sink.insert_stream(self.source.get_items(missing))
99
        # assert not missing
1240 by Martin Pool
- clean up fetch code and add progress bar
100
        self.count_total = 0
1185.33.55 by Martin Pool
[patch] weave fetch optimizations (Goffredo Baroncelli)
101
        self.file_ids_names = {}
4110.2.9 by Martin Pool
Re-add very basic top-level pb for fetch
102
        pb = bzrlib.ui.ui_factory.nested_progress_bar()
4110.2.14 by Martin Pool
Small fetch progress tweaks
103
        pb.show_pct = pb.show_count = False
4110.2.9 by Martin Pool
Re-add very basic top-level pb for fetch
104
        try:
4110.2.14 by Martin Pool
Small fetch progress tweaks
105
            pb.update("Finding revisions", 0, 2)
4110.2.9 by Martin Pool
Re-add very basic top-level pb for fetch
106
            search = self._revids_to_fetch()
107
            if search is None:
108
                return
4110.2.14 by Martin Pool
Small fetch progress tweaks
109
            pb.update("Fetching revisions", 1, 2)
4110.2.9 by Martin Pool
Re-add very basic top-level pb for fetch
110
            self._fetch_everything_for_search(search)
111
        finally:
112
            pb.finished()
2535.3.6 by Andrew Bennetts
Move some "what repo data to fetch logic" from RepoFetcher to Repository.
113
4110.2.6 by Martin Pool
Remove more progressbar cruft from fetch
114
    def _fetch_everything_for_search(self, search):
2535.3.6 by Andrew Bennetts
Move some "what repo data to fetch logic" from RepoFetcher to Repository.
115
        """Fetch all data for the given set of revisions."""
2535.3.9 by Andrew Bennetts
More comments.
116
        # The first phase is "file".  We pass the progress bar for it directly
2668.2.8 by Andrew Bennetts
Rename get_data_to_fetch_for_revision_ids as item_keys_introduced_by.
117
        # into item_keys_introduced_by, which has more information about how
2535.3.9 by Andrew Bennetts
More comments.
118
        # that phase is progressing than we do.  Progress updates for the other
119
        # phases are taken care of in this function.
120
        # XXX: there should be a clear owner of the progress reporting.  Perhaps
2668.2.8 by Andrew Bennetts
Rename get_data_to_fetch_for_revision_ids as item_keys_introduced_by.
121
        # item_keys_introduced_by should have a richer API than it does at the
122
        # moment, so that it can feed the progress information back to this
2535.3.9 by Andrew Bennetts
More comments.
123
        # function?
4060.1.3 by Robert Collins
Implement the separate source component for fetch - repository.StreamSource.
124
        if (self.from_repository._format.rich_root_data and
125
            not self.to_repository._format.rich_root_data):
126
            raise errors.IncompatibleRepositories(
127
                self.from_repository, self.to_repository,
128
                "different rich-root support")
4110.2.6 by Martin Pool
Remove more progressbar cruft from fetch
129
        pb = bzrlib.ui.ui_factory.nested_progress_bar()
2535.3.7 by Andrew Bennetts
Remove now unused _fetch_weave_texts, make progress reporting closer to how it was before I refactored __fetch.
130
        try:
4110.2.12 by Martin Pool
Add more fetch progress
131
            pb.update("Get stream source")
4060.1.3 by Robert Collins
Implement the separate source component for fetch - repository.StreamSource.
132
            source = self.from_repository._get_source(
133
                self.to_repository._format)
134
            stream = source.get_stream(search)
4022.1.1 by Robert Collins
Refactoring of fetch to have a sender and sink component enabling splitting the logic over a network stream. (Robert Collins, Andrew Bennetts)
135
            from_format = self.from_repository._format
4110.2.12 by Martin Pool
Add more fetch progress
136
            pb.update("Inserting stream")
4032.3.7 by Robert Collins
Move write locking and write group responsibilities into the Sink objects themselves, allowing complete avoidance of unnecessary calls when the sink is a RemoteSink.
137
            resume_tokens, missing_keys = self.sink.insert_stream(
138
                stream, from_format, [])
4257.3.2 by Andrew Bennetts
Check during fetch if we are going to be missing data necessary to calculate altered fileids for stacked revisions.
139
            if self.to_repository._fallback_repositories:
4241.18.1 by Andrew Bennetts
Cherry pick stacking push fix from bzr.dev r4289, make a 'Changes from RC1 to Final' section in NEWS.
140
                missing_keys.update(
4257.4.12 by Andrew Bennetts
Move _parent_inventories helper to RepoFetcher.
141
                    self._parent_inventories(search.get_keys()))
4029.2.1 by Robert Collins
Support streaming push to stacked branches.
142
            if missing_keys:
4110.2.12 by Martin Pool
Add more fetch progress
143
                pb.update("Missing keys")
4060.1.3 by Robert Collins
Implement the separate source component for fetch - repository.StreamSource.
144
                stream = source.get_stream_for_missing_keys(missing_keys)
4110.2.12 by Martin Pool
Add more fetch progress
145
                pb.update("Inserting missing keys")
4032.3.7 by Robert Collins
Move write locking and write group responsibilities into the Sink objects themselves, allowing complete avoidance of unnecessary calls when the sink is a RemoteSink.
146
                resume_tokens, missing_keys = self.sink.insert_stream(
147
                    stream, from_format, resume_tokens)
4029.2.1 by Robert Collins
Support streaming push to stacked branches.
148
            if missing_keys:
149
                raise AssertionError(
150
                    "second push failed to complete a fetch %r." % (
151
                        missing_keys,))
4032.3.7 by Robert Collins
Move write locking and write group responsibilities into the Sink objects themselves, allowing complete avoidance of unnecessary calls when the sink is a RemoteSink.
152
            if resume_tokens:
153
                raise AssertionError(
154
                    "second push failed to commit the fetch %r." % (
155
                        resume_tokens,))
4110.2.12 by Martin Pool
Add more fetch progress
156
            pb.update("Finishing stream")
4022.1.1 by Robert Collins
Refactoring of fetch to have a sender and sink component enabling splitting the logic over a network stream. (Robert Collins, Andrew Bennetts)
157
            self.sink.finished()
2535.3.7 by Andrew Bennetts
Remove now unused _fetch_weave_texts, make progress reporting closer to how it was before I refactored __fetch.
158
        finally:
4110.2.6 by Martin Pool
Remove more progressbar cruft from fetch
159
            pb.finished()
4029.2.1 by Robert Collins
Support streaming push to stacked branches.
160
1185.65.30 by Robert Collins
Merge integration.
161
    def _revids_to_fetch(self):
2535.3.7 by Andrew Bennetts
Remove now unused _fetch_weave_texts, make progress reporting closer to how it was before I refactored __fetch.
162
        """Determines the exact revisions needed from self.from_repository to
163
        install self._last_revision in self.to_repository.
164
165
        If no revisions need to be fetched, then this just returns None.
166
        """
4070.9.2 by Andrew Bennetts
Rough prototype of allowing a SearchResult to be passed to fetch, and using that to improve network conversations.
167
        if self._fetch_spec is not None:
168
            return self._fetch_spec
4110.2.22 by Martin Pool
Re-add mutter calls during fetch
169
        mutter('fetch up to rev {%s}', self._last_revision)
1534.4.50 by Robert Collins
Got the bzrdir api straightened out, plenty of refactoring to use it pending, but the api is up and running.
170
        if self._last_revision is NULL_REVISION:
171
            # explicit limit of no revisions needed
3184.1.9 by Robert Collins
* ``Repository.get_data_stream`` is now deprecated in favour of
172
            return None
4316.1.3 by Jonathan Lange
Don't bother wrapping the NoSuchRevision in an InstallFailed.
173
        return self.to_repository.search_missing_revision_ids(
174
            self.from_repository, self._last_revision,
175
            find_ghosts=self.find_ghosts)
1185.64.3 by Goffredo Baroncelli
This patch changes the fetch code. Before, the original code expanded every inventory and
176
4257.4.12 by Andrew Bennetts
Move _parent_inventories helper to RepoFetcher.
177
    def _parent_inventories(self, revision_ids):
178
        # Find all the parent revisions referenced by the stream, but
4257.4.13 by Andrew Bennetts
Tweak comment.
179
        # not present in the stream, and make sure we send their
4257.4.12 by Andrew Bennetts
Move _parent_inventories helper to RepoFetcher.
180
        # inventories.
181
        parent_maps = self.to_repository.get_parent_map(revision_ids)
182
        parents = set()
183
        map(parents.update, parent_maps.itervalues())
184
        parents.discard(NULL_REVISION)
185
        parents.difference_update(revision_ids)
186
        missing_keys = set(('inventories', rev_id) for rev_id in parents)
187
        return missing_keys
188
3565.3.3 by Robert Collins
* Fetching data between repositories that have the same model but no
189
1910.2.24 by Aaron Bentley
Got intra-repository fetch working between model1 and 2 for all types
190
class Inter1and2Helper(object):
1910.2.48 by Aaron Bentley
Update from review comments
191
    """Helper for operations that convert data from model 1 and 2
3943.8.1 by Marius Kruger
remove all trailing whitespace from bzr source
192
1910.2.48 by Aaron Bentley
Update from review comments
193
    This is for use by fetchers and converters.
194
    """
195
4022.1.1 by Robert Collins
Refactoring of fetch to have a sender and sink component enabling splitting the logic over a network stream. (Robert Collins, Andrew Bennetts)
196
    def __init__(self, source):
1910.2.48 by Aaron Bentley
Update from review comments
197
        """Constructor.
198
199
        :param source: The repository data comes from
200
        """
201
        self.source = source
202
203
    def iter_rev_trees(self, revs):
204
        """Iterate through RevisionTrees efficiently.
205
206
        Additionally, the inventory's revision_id is set if unset.
207
208
        Trees are retrieved in batches of 100, and then yielded in the order
209
        they were requested.
210
211
        :param revs: A list of revision ids
212
        """
3172.4.4 by Robert Collins
Review feedback.
213
        # In case that revs is not a list.
214
        revs = list(revs)
1910.2.48 by Aaron Bentley
Update from review comments
215
        while revs:
216
            for tree in self.source.revision_trees(revs[:100]):
1910.2.44 by Aaron Bentley
Retrieve only 500 revision trees at once
217
                if tree.inventory.revision_id is None:
218
                    tree.inventory.revision_id = tree.get_revision_id()
219
                yield tree
1910.2.48 by Aaron Bentley
Update from review comments
220
            revs = revs[100:]
1910.2.44 by Aaron Bentley
Retrieve only 500 revision trees at once
221
3380.2.4 by Aaron Bentley
Updates from review
222
    def _find_root_ids(self, revs, parent_map, graph):
223
        revision_root = {}
1910.2.48 by Aaron Bentley
Update from review comments
224
        for tree in self.iter_rev_trees(revs):
1910.2.18 by Aaron Bentley
Implement creation of knits for tree roots
225
            revision_id = tree.inventory.root.revision
2946.3.3 by John Arbash Meinel
Prefer tree.get_root_id() as more explicit than tree.path2id('')
226
            root_id = tree.get_root_id()
3380.1.3 by Aaron Bentley
Fix model-change fetching with ghosts and when fetch is resumed
227
            revision_root[revision_id] = root_id
228
        # Find out which parents we don't already know root ids for
229
        parents = set()
230
        for revision_parents in parent_map.itervalues():
231
            parents.update(revision_parents)
232
        parents.difference_update(revision_root.keys() + [NULL_REVISION])
3380.2.7 by Aaron Bentley
Update docs
233
        # Limit to revisions present in the versionedfile
3380.1.3 by Aaron Bentley
Fix model-change fetching with ghosts and when fetch is resumed
234
        parents = graph.get_parent_map(parents).keys()
235
        for tree in self.iter_rev_trees(parents):
236
            root_id = tree.get_root_id()
237
            revision_root[tree.get_revision_id()] = root_id
4476.3.11 by Andrew Bennetts
All fetch and interrepo tests passing.
238
        return revision_root
3380.2.4 by Aaron Bentley
Updates from review
239
240
    def generate_root_texts(self, revs):
241
        """Generate VersionedFiles for all root ids.
242
243
        :param revs: the revisions to include
244
        """
245
        graph = self.source.get_graph()
246
        parent_map = graph.get_parent_map(revs)
4476.3.9 by Andrew Bennetts
Further reduce duplication.
247
        rev_order = tsort.topo_sort(parent_map)
4476.3.11 by Andrew Bennetts
All fetch and interrepo tests passing.
248
        rev_id_to_root_id = self._find_root_ids(revs, parent_map, graph)
3350.6.4 by Robert Collins
First cut at pluralised VersionedFiles. Some rather massive API incompatabilities, primarily because of the difficulty of coherence among competing stores.
249
        root_id_order = [(rev_id_to_root_id[rev_id], rev_id) for rev_id in
250
            rev_order]
251
        # Guaranteed stable, this groups all the file id operations together
252
        # retaining topological order within the revisions of a file id.
253
        # File id splits and joins would invalidate this, but they don't exist
254
        # yet, and are unlikely to in non-rich-root environments anyway.
255
        root_id_order.sort(key=operator.itemgetter(0))
256
        # Create a record stream containing the roots to create.
4476.3.41 by Andrew Bennetts
Use FrozenHeadsCache to speed up root generation.
257
        from bzrlib.graph import FrozenHeadsCache
258
        graph = FrozenHeadsCache(graph)
4476.3.9 by Andrew Bennetts
Further reduce duplication.
259
        new_roots_stream = _new_root_data_stream(
4476.3.41 by Andrew Bennetts
Use FrozenHeadsCache to speed up root generation.
260
            root_id_order, rev_id_to_root_id, parent_map, self.source, graph)
4476.3.9 by Andrew Bennetts
Further reduce duplication.
261
        return [('texts', new_roots_stream)]
262
263
264
def _new_root_data_stream(
4476.3.41 by Andrew Bennetts
Use FrozenHeadsCache to speed up root generation.
265
    root_keys_to_create, rev_id_to_root_id_map, parent_map, repo, graph=None):
4476.3.9 by Andrew Bennetts
Further reduce duplication.
266
    for root_key in root_keys_to_create:
267
        root_id, rev_id = root_key
268
        parent_keys = _parent_keys_for_root_version(
4476.3.41 by Andrew Bennetts
Use FrozenHeadsCache to speed up root generation.
269
            root_id, rev_id, rev_id_to_root_id_map, parent_map, repo, graph)
4476.3.9 by Andrew Bennetts
Further reduce duplication.
270
        yield versionedfile.FulltextContentFactory(
271
            root_key, parent_keys, None, '')
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
272
273
274
def _parent_keys_for_root_version(
4476.3.41 by Andrew Bennetts
Use FrozenHeadsCache to speed up root generation.
275
    root_id, rev_id, rev_id_to_root_id_map, parent_map, repo, graph=None):
4476.3.7 by Andrew Bennetts
Improve docstring.
276
    """Get the parent keys for a given root id."""
4476.3.9 by Andrew Bennetts
Further reduce duplication.
277
    # Include direct parents of the revision, but only if they used the same
278
    # root_id and are heads.
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
279
    rev_parents = parent_map[rev_id]
280
    parent_ids = []
281
    for parent_id in rev_parents:
282
        if parent_id == NULL_REVISION:
283
            continue
284
        if parent_id not in rev_id_to_root_id_map:
4476.3.9 by Andrew Bennetts
Further reduce duplication.
285
            # We probably didn't read this revision, go spend the extra effort
286
            # to actually check
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
287
            try:
288
                tree = repo.revision_tree(parent_id)
289
            except errors.NoSuchRevision:
4476.3.9 by Andrew Bennetts
Further reduce duplication.
290
                # Ghost, fill out rev_id_to_root_id in case we encounter this
291
                # again.
292
                # But set parent_root_id to None since we don't really know
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
293
                parent_root_id = None
294
            else:
295
                parent_root_id = tree.get_root_id()
296
            rev_id_to_root_id_map[parent_id] = None
4476.3.21 by Andrew Bennetts
Clarify some code and comments, and s/1.17/1.18/ in a few places.
297
            # XXX: why not:
298
            #   rev_id_to_root_id_map[parent_id] = parent_root_id
299
            # memory consumption maybe?
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
300
        else:
301
            parent_root_id = rev_id_to_root_id_map[parent_id]
302
        if root_id == parent_root_id:
4476.3.9 by Andrew Bennetts
Further reduce duplication.
303
            # With stacking we _might_ want to refer to a non-local revision,
304
            # but this code path only applies when we have the full content
305
            # available, so ghosts really are ghosts, not just the edge of
306
            # local data.
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
307
            parent_ids.append(parent_id)
308
        else:
309
            # root_id may be in the parent anyway.
310
            try:
311
                tree = repo.revision_tree(parent_id)
312
            except errors.NoSuchRevision:
313
                # ghost, can't refer to it.
314
                pass
315
            else:
316
                try:
4476.3.9 by Andrew Bennetts
Further reduce duplication.
317
                    parent_ids.append(tree.inventory[root_id].revision)
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
318
                except errors.NoSuchId:
319
                    # not in the tree
320
                    pass
321
    # Drop non-head parents
4476.3.41 by Andrew Bennetts
Use FrozenHeadsCache to speed up root generation.
322
    if graph is None:
323
        graph = repo.get_graph()
324
    heads = graph.heads(parent_ids)
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
325
    selected_ids = []
326
    for parent_id in parent_ids:
327
        if parent_id in heads and parent_id not in selected_ids:
328
            selected_ids.append(parent_id)
4476.3.9 by Andrew Bennetts
Further reduce duplication.
329
    parent_keys = [(root_id, parent_id) for parent_id in selected_ids]
4476.3.6 by Andrew Bennetts
Refactor out duplicated get parent keys logic from Inter1and2Helper and InterDifferingSerializer.
330
    return parent_keys